You are not alone if spiders intrigue you, and you often wonder about interesting facts related to them. There are a lot of interesting facts about arachnids. One prevalent assumption is that spiders have multiple eyes; however, do all spiders have multiple eyes, and how many eyes does a spider have? Well, let’s find out!
Table of Contents
Revising the Spider basics.
Spiders (Araneae) are one of the most varied groups of arthropods on the planet, with approximately 43,000 different species.
These critters are common bugs that can easily adapt to living in human environments. Spiders use their silk webs to cover dark places in different families’ houses.
As for their anatomical structures, spiders come in various shapes and sizes, depending on their tasks. Some spiders have more eyes than others, and some have none at all, a trait that evolves in spider species based on where they live.
Do You Know how many eyes does a spider have?
Similar to any living species on this planet, spiders come in a variety of shapes and sizes, and this variation extends to the number of eyes as well.
Thereby, simplifying this answer for you, I can safely say that the number of eyes a spider has can depend on the species, its environment, climate change, and other living factors.
That being said, while, on average eight-eyed spiders are common, there are many different types of spiders that have fewer, more eyes. or no eyes at all!
Interestingly, the number of eyes a spider has helps classify the family of the spider. For example, tarantulas have eight eyes while most spiders have six. This characteristic is one way to help identify different types of spiders.
What does the Purpose of Spiders have So Many Eyes?
Did you know that while some people believe that spiders’ eyes are just an evolutionary adaptation that helps them survive, research shows that they could be potential motion-detecting organs?
Consequently, the reason behind these critters possessing multiple eyes is highly variable.
Let me explain,
One of the most common reasons, according to the studies, is the relation of multiple eyes with the need to be able to detect motion. This is especially important for them because they are predators and rely on being able to ambush their prey.
Therefore, while the primary eyes (with the sharp, colored vision allowing them to detect ultraviolet light that humans cannot see) are used for basic perception, the spiders’ ability to react to hunting is highly aided by the presence of additional eyes.
The more eyes a spider has, the better its chances of detecting movement and catching its prey.
Furthermore, by having eyes on the side of their head, they can see in all directions at once and better evade danger.
How Good Is Spiders Vision?
It is known that spiders need good vision for some activities, such as web building and hunting.
For example, a spider’s ability to build a web is hindered without good vision because it needs to be able to accurately place the sticky silk. In terms of hunting, spiders rely on their eyesight to identify prey from a distance.
How many eyes does a house spider have?
The house spider is a night-time arthropod that has difficulty seeing and perceiving items in low light or darkness. When there is light, these spiders use their eyes to detect movement. They rely on other portions of their bodies to feel what is happening around them.
With the use of their legs and the front eye on their head, most house spiders spin webs and hunt small insects and small types of animals.
As for the number of eyes, the house spider can have anywhere from a few to many eyes.
I have explained this thoroughly in the next section, so let’s move on.
Common house spiders and the intriguing configuration of their eyes.
House spiders come in a variety of shapes and sizes. They are the most common members of the Spider family you may likely happen upon.
Therefore, let us investigate and learn more about the peeper you might encounter on spiders invading your home!
Domestic house spider
The color pattern of this spider is common, ranging from dark orange to brown. These spiders, sometimes known as barn funnel weavers, have eight eyes.
This enables these critters to detect even the tiniest movement from prey or potential attackers. Because their vision is poor, they are more likely to detect movement than anything else.
Many spiders are nocturnal, meaning they hunt at night. However, a few species of spiders hunt during the day. These spiders rely on their excellent vision to catch unsuspecting insects.
Daylight Hunting Spiders and Their Eyes
Some daylight hunting spiders have eyesight that is almost as good as humans’. This means they can see their prey from a distance and hunt during the day.
What’s more, researchers believe daylight hunting spiders use their two pairs of side-eyes to detect the motion of their prey.
The front eyes are usually used for identifying objects, but because the prey is usually stationary, the side eyes play a more important role in detecting movement.
Brown House Spider
Well, this member of the spider family is the critter I have had the personal experience encountering.
Quite understandable, as the Brown House Spider is one of the most common spiders found throughout the world.
They are typically around 1 inch long and have a reddish-brown color. They build their webs in the dark, secluded areas such as basements, sheds, garages, and other outbuildings.
These spiders also have eight eyes, which aids them in hunting and avoiding any predators.
Wolf Spiders’ Eyes
Wolf spiders forage at night or under the light of the moon. Their four huge posterior eyes are similar to a cat’s eyes in that they are extremely sensitive to low light levels and reflect strongly when light is shone onto them.
When hunting in low light, the wolf spider has a significant advantage.
Black House Spiders
Black house spiders, like most spiders, typically aren’t considered dangerous to humans. However, they can be quite dangerous to their prey. They spin webs near the ground in dark and damp areas, such as under rocks or logs.
Like most of their relatives, these spider family members also possess about eights.
Giant House Spiders
The Giant House Spider is typically found in caves and outdoors, but it is becoming more common in homes as they invade webs. These spiders are typically harmless to humans but should not be touched as their bite can be painful.
Interestingly, giant house spiders have eight eyes, which are arranged in two sets of four. This allows them to have a wide field of view and detect movement from all directions.
Net-Casting Spiders’ Eyes
Most spiders have eight eyes, but net-casting spiders have two large eyes that give them their nickname – “the ogre-faced spiders.” These eyes are used to detect prey in the dark.
Their eyes are set on the sides of their head, giving them a wide field of vision. This allows them to see potential prey even in a very dim light.
What’s more, did you know that net-casting spiders have a very interesting eye structure? Every night, a new membrane is produced in an eye, and the previous night’s membrane is destroyed every morning.
This means that the spider can always see clearly, no matter how many times it has to replace its eyesight during the day.
The interesting case of Spiders without Eye!
There are a surprising number of spiders that lack eyes, such as the cave-dwelling huntsman Sinopoda scurion.
This is because they have evolved to live in dark and confined spaces, where their need for vision is not as important. Most eyeless spiders are very small and live in the crevices of rocks or in leaf litter on the ground.
Interestingly, these spiders can hunt and survive without their eyes. This is particularly facilitated by relying on their keen sense of smell to detect prey, which they capture using their powerful venomous fangs.
In conclusion, spider eyesight varies depending on the type of spider and its hunting methods.
As you know, some spiders have excellent eyesight to better navigate their surroundings, hunt their prey, and evade predators. In contrast, others may only need a few eyes in order to see basic movement and shapes.
What’s more, there can be spiders with no sight at all, relying on their webs and other sensations to trap prey.